Push-pull Control Cable - Patent 6347561

1. Field of the InventionThe present invention relates to a push-pull control cable for transmitting an operation effort in pushing and pulling directions.2. Description of the Prior ArtIn Japanese Patent Laid-open Publication No. 7(1995)26646, there has been proposed a push-pull type control cable including an inner cable comprised of a plurality of strands each formed by more than five pieces of twisted element wires and woundaround a core wire, the inner cable being inserted into a conduit tube to be displaced in an axial direction for transmitting an operation effort applied to its one end at a push-side or a pull-side. In use of the control cable, lubricant is filled in aclearance between the inner periphery of the conduit tube and the outer periphery of the inner cable to reduce friction of the inner cable in the conduit tube thereby to enhance load efficiency and durability of the control cable. In the conventionalcontrol cable, however, a sufficient amount of lubricant may not be filled in the clearance between the inner cable and the conduit tube. As a result, the enhanced load efficiency and durability of the control cable may not be maintained for a longperiod of time.SUMMARY OF THE INVENTIONAn object of the present invention is to provide a push-pull type control cable the load efficiency and durability of which are maintained in an enhanced condition for a long period of time.According to the present invention, the object is accomplished by providing a push-pull type control cable having a conduit tube and an inner cable comprised of a core wire and a plurality of strands wound around the core wire and inserted intothe conduit tube, the control cable being filled with lubricant at a clearance between an inner periphery of the conduit tube and an outer periphery of the inner cable, wherein the plurality of strands each are comprised of three pieces of element wirestwisted in a manner of ordinary lay (twisted in a reverse direction relative to the wi

United States Patent: 6347561
&nbsp;
( 1 of 1 )
United States Patent
6,347,561
Uneme
, &nbsp; et al.
February 19, 2002
Push-pull control cable
Abstract
A push-pull type control cable having a conduit tube and an inner cable
comprised of a core wire and a plurality of strands wound around the core
wire and inserted into the conduit tube, the control cable being filled
with lubricant at a clearance between an inner periphery of the conduit
tube and an outer periphery of the inner cable, wherein the plurality of
strands each are comprised of three pieces of twisted element wires.
Inventors:
Uneme; Masato (Nagoya, JP), Yamada; Seiji (Nishikamo-gun, JP), Yamada; Yasuhiro (Toyota, JP), Nagata; Koichi (Kaizuka, JP)
Assignee:
Chuo Hatsujo Kabushiki Kaisha
(Aichi-Ken,
JP)
Kabushiki Kaisha Aporon
(Osaka-Fu,
JP)
Appl. No.:
09/727,545
Filed:
December 4, 2000
Related U.S. Patent Documents
Application NumberFiling DatePatent NumberIssue Date
235761Jan., 19996203415Apr., 2001
Foreign Application Priority Data
Jan 23, 1998
[JP]
10-11845
Current U.S. Class:
74/502.5 ; 74/500.5; 74/501.5R
Current International Class:
F16C 1/20&nbsp(20060101); F16C 1/00&nbsp(20060101); F16C 1/26&nbsp(20060101); F16C 1/10&nbsp(20060101); F16C 001/10&nbsp()
Field of Search:
74/501.5 R-502.6/ 428/36
References Cited [Referenced By]
U.S. Patent Documents
4112708
September 1978
Fukuda
4300408
November 1981
Yoshifuji
4362069
December 1982
Giatras et al.
4951523
August 1990
Shiota et al.
5038834
August 1991
Siegfried
5195393
March 1993
Wolfington et al.
5243876
September 1993
Mang et al.
5245887
September 1993
Tanaka et al.
5636551
June 1997
Davidson et al.
5659152
August 1997
Horie et al.
5802929
September 1998
Furukawa et al.
6078010
June 2000
Funahashi et al.
6194466
February 2001
Hayashida et al.
Foreign Patent Documents
514602
Jul., 1955
CA
6-200918
Jul., 1955
JP
62-292912
Dec., 1987
JP
4-327017
Nov., 1992
JP
7-26646
Mar., 1995
JP
7-130228
May., 1995
JP
Primary Examiner: Luong; Vinh T.
Attorney, Agent or Firm: Reed Smith Hazel & Thomas LLP
Parent Case Text
This application is a continuation application based on FIGS. 7 to 8 of the
pending application Ser. No. 09/235,761 filed on Jan. 25, 1999 now U.S.
Pat. No. 6,203,415 B1 issued on Apr. 3, 2001.
Claims
What is claimed is:
1. A push-pull type control cable having an inner cable comprised of a strand formed by three pieces of twisted element wires and a single wire alternately wound around a core
wire and inserted into a conduit tube, the control cable being filled with lubricant in a clearance between an inner periphery of the conduit tube and an outer periphery of the inner cable.
2. A push-pull type control cable having a conduit tube and an inner cable comprised of a core wire with a plurality of strands and a single wire alternately wound around the core wire and inserted into the conduit tube, the control cable being
filled with lubricant in a clearance between an inner periphery of the conduit tube and an outer periphery of the inner cable,
wherein the strands are each comprised of three pieces of element wires twisted in a manner of ordinary lay or in a reverse direction relative to the winding direction of the strands, while the single wire is smaller in diameter than each of the
strands.
3. A push-pull type control cable as claimed in claim 2, wherein the single wire is made of the same material as that of the element wires.
4. A push-pull type control cable as claimed in claim 2, wherein the element wires of the strands each are made of at least one of a plated hard steel wire and a stainless steel wire.
5. A push-pull type control cable as claimed in claim 2, wherein the core wire is made of at least one of a stainless wire, an oil-temper wire, a bluing wire, a heat-stretch wire and a piano wire. Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a push-pull control cable for transmitting an operation effort in pushing and pulling directions.
2. Description of the Prior Art
In Japanese Patent Laid-open Publication No. 7(1995)26646, there has been proposed a push-pull type control cable including an inner cable comprised of a plurality of strands each formed by more than five pieces of twisted element wires and wound
around a core wire, the inner cable being inserted into a conduit tube to be displaced in an axial direction for transmitting an operation effort applied to its one end at a push-side or a pull-side. In use of the control cable, lubricant is filled in a
clearance between the inner periphery of the conduit tube and the outer periphery of the inner cable to reduce friction of the inner cable in the conduit tube thereby to enhance load efficiency and durability of the control cable. In the conventional
control cable, however, a sufficient amount of lubricant may not be filled in the clearance between the inner cable and the conduit tube. As a result, the enhanced load efficiency and durability of the control cable may not be maintained for a long
period of time.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a push-pull type control cable the load efficiency and durability of which are maintained in an enhanced condition for a long period of time.
According to the present invention, the object is accomplished by providing a push-pull type control cable having a conduit tube and an inner cable comprised of a core wire and a plurality of strands wound around the core wire and inserted into
the conduit tube, the control cable being filled with lubricant at a clearance between an inner periphery of the conduit tube and an outer periphery of the inner cable, wherein the plurality of strands each are comprised of three pieces of element wires
twisted in a manner of ordinary lay (twisted in a reverse direction relative to the winding direction of the strands. In the push-pull type control cable, a sufficient amount of lubricant is filled in a clearance between the outer periphery of the inner
cable and the inner periphery of the conduit tube since rugged surfaces larger in roughness are formed on the strands of the inner cable. This is useful to maintain load efficiency and durability of the control cable in an enhanced condition for a long
period of time. As the element wires each are relatively large in diameter to enhance each bending stiffness of the strands in a small diameter, the buckling strength of the inner cable can be increased to enhance operability of the control cable. As
the outer peripheral area of the inner cable in contact with the inner periphery of the conduit tube is reduced, friction of the inner cable caused by displacement in the conduit tube can be decreased to enhance the load efficiency of the control cable.
In addition, the three pieces of element wires of each strand are twisted in such a manner that each element wire is pressed into contact with other two element wires to maintain the configuration of each strand for a long period of time.
In actual practices of the present invention, it is desirable that the plurality of strands each are comprised of three pieces of element wires twisted in a manner of ordinary lay (twisted in a reverse direction relative to the winding direction
of the strands around the core wire). In the strands of the inner cable, the element wires are stranded at a small angle relative to the axial direction of the inner cable to enhance the buckling strength of the inner cable. As the element wires
appeared on the inner cable are aligned in parallel in the axial direction of the inner cable, the friction of the inner cable caused by displacement in the conduit tube is reduced to enhance the load efficiency and durability of the control cable.
In actual practices of the present invention, the plurality of strands may be provided in the form of a plurality of first strands each comprised of twisted element wires of large diameter twisted in a manner of ordinary (twisted in a reverse
direction relative to the winding direction of the first strands and a plurality of second strands comprised of element wires of small diameter twisted in the same manner as in the first strands, wherein the first and second strands are alternately wound
around the core wire. With such an arrangement, a sufficient amount of lubricant can be filled in a clearance between the second strands and the inner periphery of the conduit tube to maintain the load efficiency and durability of the control cable in
an enhanced condition for a long period of time. In addition, the load efficiency of the control cable is further enhanced as the outer peripheral area of the inner cable in contact with the inner periphery of the conduit tube is reduced.
In actual practices of the present invention, the plurality of strands may be provided in the form of a plurality of first strands each comprised of three pieces of element wires twisted in a manner of ordinary lay and a plurality of second
strands each comprised of three pieces of element wires twisted in a manner of langs lay (twisted in the same direction as the winding direction of the strands on the core wire), wherein the first and second strands are alternately wound around the core
wire. With this arrangement, the operability, load efficiency and durability of the control cable can be enhanced, and the elasticity of the inner cable can be enhanced since the angle of the element wires relative to the axis line of the inner cable is
increased.
In the above arrangement, the first strands each may be comprised of stranded element wires of large diameter, while the second strands each may be comprised of twisted element wires of small diameter. With this arrangement, a sufficient amount
of lubricant can be filled to maintain the load efficiency and durability of the control cable in an enhanced condition for a long period of time. In this case, the friction caused by axial displacement of the inner cable in the conduit tube is reduced
since only the first strands formed in the ordinary lay are in contact with the inner periphery of the conduit tube. This serves to enhance the elasticity of the control cable without causing deterioration of the load efficiency and durability.
Furthermore, the push-pull type control cable may be provided in the form of a control cable having an inner cable comprised of a strand formed by three pieces of twisted element wires and a single wire of small diameter alternately wound around
a core wire and inserted into a conduit tube, the control cable being filled with lubricant at a clearance between an inner periphery of the conduit tube and an outer periphery of the inner cable.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a component of a push-pull type control cable in a preferred embodiment of the present invention;
FIG. 2 is a cross-sectional view of the control cable of the invention taken on plane I--I of FIG. 1;
FIG. 3 is a perspective view of a first modification of the inner cable shown in FIG. 1;
FIG. 4 is a cross-sectional view of the first modification;
FIG. 5(a) is a second modification of the inner cable shown in FIG. 1, FIG. 5(b) is a cross sectional view of a control cable shown in FIG. 5(a);
FIG. 6 is a third modification of the inner cable shown in FIG. 1;
FIG. 7(a) is a perspective view of a fourth modification of the inner cable shown in FIG. 1; FIG. 7(b) is a cross-sectional view of the control cable with the fourth modification shown in FIG. 7(a);
FIG. 8 is a cross-sectional view of the fourth modification of the invention taken on plane III--III of FIG. 7(b).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. FIG. 1 illustrates a component of a push-pull control cable in the preferred embodiment, and FIG. 2 illustrates a cross-section of the
control cable. The control cable is composed of a conduit tube 10 and an inner cable 20.
The conduit tube 10 is comprised of a liner 11 in the form of a hollow cable of synthetic resin, a plurality of strands 12 each formed by twisted element wires (for example, plated hard steel wires, stainless wires, etc.) and wound around the
liner 11 and ajacket of synthetic resin covering the strands 12. The conduit tube 10 is flexible in its entirety.
The inner cable 20 is comprised of a core wire 21 and a plurality of strands (in this embodiment, ten pieces of strands) wound around the core wire 21. The inner cable 20 is flexible in its entirety and inserted into the liner 11 of conduit tube
10. The core wire 21 is made of a material superior in straightness (for example, a stainless wire, an oil-temper wire, a bluing wire, a heat-stretch wire, a piano wire, etc.). The strands 22 each are comprised of three pieces of element wires 22a (for
example, plated hard steel wires, stainless wires, etc.) twisted in a manner of ordinary lay. As shown in FIG. 2, a clearance between the outer periphery of inner cable 20 and the inner periphery of liner 11 of conduit tube is filled with an amount of
lubricant such as grease G.
In the push-pull type control cable, the inner cable in conduit tube is displaced by an operation effort applied at one end at a push-side or pull-side for transmitting the operation effort to the other end. In such an instance, each strand 12
of the conduit tube 10 acts to enhance bending stiffness of the conduit tube 10 for supporting displacement reaction of the inner cable 20, and the grease G serves to reduce friction of the inner cable 20 in the conduit tube 10. This is useful to
enhance the load efficiency and durability of the control cable. In the control cable, it is to be noted that the strands 22 each are comprised of three pieces of element wires twisted to form rugged surfaces larger in roughness than those in a
conventional push-pull type control cable. With such construction of the strands 20, a sufficient amount of grease G can be filled in the clearance between the inner cable 20 and the liner 11 of conduit tube 10. This is useful to maintain the enhanced
load efficiency and durability of the control cable for a long period of time.
As the element wires 22a each are relatively large in diameter to enhance each bending stiffness of the strands 22 in a small diameter, the buckling strength of the inner cable 20 can be increased to reduce backlash of the control cable. As the
outer peripheral area of the inner cable 20 in contact with the inner periphery of the conduit tube 10 is reduced, the friction of inner cable 20 caused by displacement in the conduit tube 10 can be decreased to enhance the load efficiency of the control
cable. In addition, the three pieces of element wires 22a of the respective strands 22 are twisted in such a manner that each element wire is pressed into contact with other two element wires to maintain the configuration of each strand 22 for a long
period of time.
In each of the strands 22, the element wires 22a are twisted in a manner of ordinary lay at a small angle relative to the axial direction of the inner cable 20 to enhance the buckling strength of the inner cable 20. As the element wires 22a
exposed on the inner cable 20 are aligned in parallel in the axial direction of inner cable 20, the friction of inner cable 20 caused by displacement in the conduit tube 10 is reduced to enhance the load efficiency and durability of the control cable.
Hereinafter, first to fourth modifications of the above embodiment will be described with reference to the drawings.
First Modification
Illustrated in FIG. 3 is a first modification of the control cable wherein an inner cable 30 is substituted for the inner cable 20 in the preferred embodiment. FIG. 4 illustrates a cross-section of the control cable in the first modification.
The inner cable 30 is comprised of a core wire 31 of material superior in straightness similar to the core wire 21 of the inner cable 20 and a plurality of first and second strands 32 and 33 alternately wound around the outer periphery of core wire 31.
The inner cable 30 is flexible in its entirety and inserted into the liner 11 of conduit tube 10. Similarly to the strands 22 of the inner cable 20, the first strands 32 each are comprised of three pieces of element wires 32 (for example, plated hard
steel wires, stainless wires, etc.) twisted in a manner of ordinary lay, while the second strands 33 each are comprised of three pieces of element wires 33a twisted in a manner of ordinary lay. The element wires 33a each are made of the same material as
the element wires 32a and formed smaller in diameter than the element wire 32a to provide the second strands 33 each slightly smaller in diameter than the first strands 32.
In the push-pull type control cable described above, the same effects to those in the preferred embodiment can be expected since the first and second strands 32 and 33 each are comprised of three pieces of element wires 32a, 33a respectively
twisted in a manner of ordinary lay. As the second strands 33 in the control cable each are formed smaller in diameter than the first strands 32, a sufficient amount of grease G can be filled in a clearance between the second strands 33 and the liner 11
of conduit tube 10 to maintain the load efficiency and durability of the control cable in an enhanced condition for a long period of time. As the outer peripheral area of inner cable 30 in contact with the inner periphery of conduit tube 10 is smaller
than the outer peripheral area of inner cable 20 in contact with the inner periphery of conduit tube 10, the load efficiency of the control cable is further enhanced.
Second Modification
Illustrated in FIG. 5 is a second modification of the control cable wherein an inner cable 40 is substituted for the inner cable 20 in the preferred embodiment. The inner cable 40 is comprised of a core wire 41 of the same material superior in
straightness as that of the core wire 21 in the inner cable 20 and a plurality of first and second strands 42 and 43 (for example, five pieces of strands) alternately wound around the core wire 41. The inner cable 40 is flexible in its entirety and
inserted into the conduit tube 10. The first strands 42 each are comprised of three pieces of element wires 42a (for example, plated hard steel wires, stainless wires, etc.) twisted in a manner of ordinary lay as well as the strands 22 of the inner
cable 20, while the second strands 43 each are comprised of three pieces of element wires 43a twisted in a manner of langs lay.
In the push-pull type control cable described above, the same effects as those in the preferred embodiment can be expected since the first and second strands 42 and 43 each are comprised of three pieces of element wires 42a, 43a and the first
strands 42 are formed in the ordinary lay. As the second strands 43 in the control cable each are formed in the langs lay so that the angle of the element wires 43a relative to the axis line of inner cable 40 is increased, the elasticity of inner cable
40 can be enhanced.
Third Modification
Illustrated in FIG. 6 is a third modification of the control cable wherein an inner cable 50 is substituted for the inner cable 20 in the preferred embodiment. In this modification, the inner cable 50 is comprised of a core wire 51 of the same
material superior in straightness as that of the core wire 21 of inner cable 20 and a plurality of first and second strands 52 and 53 (for example, six pieces of strands) alternately wound around the core wire 51. The inner cable 50 is flexible in its
entirety and inserted into the conduit tube 10. The first strands 52 each are comprised of three pieces of element wires (for example, plated hard steel wires, stainless wires, etc.) 52a twisted in a manner of ordinary lay as well as the strands 22 of
inner cable 20, while the second strands 53 each are comprised of three pieces of element wires 53a twisted in a manner of langs lay. The element wires 53a are made of the same material as that of the element wires 52a and formed smaller in diameter
than the element wires 52a to provide the second strands 53 slightly smaller in diameter than the first strands 52.
In the push-pull type control cable described above, the same effects as those in the preferred embodiment can be expected since the first and second strands 52 and 53 in the control cable each are comprised of three pieces of element wires 52a,
53a and the first strands 52 are formed in the manner of ordinary lay, and the same effects as those in the first modification can be expected since the second strands 53 each are formed smaller in diameter. In addition, the elasticity of the control
cable can be enhanced as in the second modification since the second strands 53 each are formed in the langs lay. In this modification, the friction caused by axial displacement of the inner cable 50 in the conduit tube 10 is reduced less than that in
the second modification since only the first strands 52 formed in the ordinary lay are in contact with the inner periphery of liner 11 of conduit tube 10. This serves to enhance the load efficiency and durability of the control cable.
Fourth Modification
Illustrated in FIG. 7 is a fourth modification of the control cable wherein an inner cable 60 is substituted for the inner cable 20 in the preferred embodiment. FIG. 8 illustrates a cross-section of the control cable in this modification. The
inner cable 60 is comprised of a core wire 61 of the same material superior in straightness as the core wire 21 of inner cable 20, a plurality of strands 62 and a single wire 63 is alternately wound around the core wire 61. The inner cable 60 is
flexible in its entirety and inserted into the liner 11 of conduit tube 10. The strands 62 each are comprised of three pieces of element wires (for example, plated hard steel wires, stainless wires, etc.) twisted in a manner of ordinary lay as well as
in the strands 22 of inner cable 20, while the single wire 63 is made of the same material as that of the element wire 62a and is formed slightly smaller in diameter than each of the strands 62.
In the push-pull type control cable described above, the same effects of those in the preferred embodiment can be expected since the strands 62 each are comprised of three pieces of element wires 62a twisted in the ordinary lay, and the same
effects as those in the first modification can be expected since the single wire 63 is formed smaller in diameter than each of the strands 62.
Although in the fourth modification, the strand each have been formed in the ordinary lay to enhance mainly the operability, durability and load efficiency of the control cable, a portion or the entirety of the strands 62 may be formed in the
langs lay to enhance the elasticity of the control cable.
* * * * *